Dicarboxylic acid esters of 3, 5-dialkoxy-1-alkanols, 3, 5, x-polyalkoxy-1-alkanols and mixtures of said alkanols



Patented Aug. 17, 1954 DICARBOXYLIC ACID ESTERS F 3,5 -DIALK-OXY-l-ALKANOLS, 3,5,X-POLYALKOXY-1- ALKANOLS AND MIXTURES 0F SAID AL-KANOLS Samuel A. Glickman and Joseph M. Wilkinson,

Easton,

Pa., assignors to General Aniline &

. Film Corporation, New York, N. Y., a corporation of Delaware NoDrawing. Application May 21, 1951, Serial No. 227,539

This invention relates to dicarboxylic acid esters of3,5-dialkoxy-1-alkanols, 3,5,x-polyalkoxy-l-alkanols, and mixtures ofsaid alkanols, and to vinyl resins, cellulose ether and estercompositions containing the same.

A large number of organic esters are known, some of which are utilizedas plasticizers for cellulose ether and ester compositions. The mostimportantproperties of any plasticizer should be compatibility withvinyl resins, cellulose ether 6 Claims. (01. 260-475) and celluloseester compositions, low volatility,

and water resistance. If a plasticizer were not completely compatible inthe proportions generally used with vinyl resins, cellulose ether orester, the plasticizer will be found to have immediately exuded from thefilm or molded piece giving generally anopaque appearance and oily feel.Sometimes this occurs only after the article or film is allowed tostand. In either case, the vinyl resins, cellulose ether or esterreverts to its original hardness and brittleness. The same thingholdstrue of low boiling plasticizers.

they boil off slowly on standing or at temperatures to which the.vinylresin or cellulose ester is subjected either in preparation oruse, the cast film or molded article again becomes brittle and mayeasily crack or break. Films, lacquers, and molded articles are oftensubjected to water in their use. If the plasticizer is water soluble toeven a small extent, the plasticizer is leached out of the vinyl resinor cellulose ester which then becomes hard and brittle. Other propertieswhich may bedesired of a plasticizer will depend on their end use. Someplasticizers will impart resistance to flammability, oils, greases, andweathering. For example, triphenyl phosphate is commonly used Where fireresistance is desired. Some plasticizers discolor ba'dlyor oxidize togive off objectionable odors. l

No one plasticizer seems to be a cure-all .for defects in use. This isprobably the reasonwhy several hundred plasticizers have been suggested.However, the majority generally fail in one or more of the previouslymentioned necessary prop.- erties of compatibility, low volatility, andwater resistance.

Most of the plasticizers currently used have the tendency whenincorporated into a vinyl resin, cellulose ether or ester to oxidize.This oxidation produces discoloration and objectionable odors. Thediscoloration or further yellowing often results at processingtemperatures due to the poor stability of the plasticizer. Dimensionstability is not maintained because of the ex oessive absorption ofwater brought on by some plasticizers. These defects, eitherindividually or collectively, render the vinyl resin, cellulose ether orester composition of little or no value for their intended use.

Of the large number of plasticizers available, the following esters havereached commercial acceptance:

Triacetin (glyceryl triacetate) Dibutyltartrate Methoxyethyl adipateMethoxyethyl oleate Triphenyl phosphate Methylphthalyl ethylglycolateDimethylphthalate Dimethoxyethylphthalate Dibutoxyethylphthalate Butylcellosolve stearate 3-methoxybutyl acetate B-utoxyethylacetacetate Theforegoing esters have not been accepted with complete satisfaction,however, because of their various defects, the principal one being thatthe esters evaporate from the vinyl resin, cellulose ether and estercomposition due to the inherent volatility of the plasticizer resultingin embrittlement on aging, poor flexibility at low temperatures whichlimits the usefulness of the cellulose ester composition. Moreover, theypossees the objectionable property of yellowing the vinyl resin orcellulose ether and ester composition when such composition is exposedto elevated temperatures of manufacture, develop objectionable odorsthrough oxidation of the plasticizer on aging, and are readily leachedfrom the plasticized composition or contact with water.

It is an object of the present invention to provide dicarboxylic acidesters of 3,5dialkoxy-lalkanols, 3,5,xpolyalkoxy-l--all anols, and mixtures of such alkanols which are not only compatible with the usualvinyl resin, cellulose ether and ester compositions but displayunusually low volatility and water resistance.

Other objects and advantages will. appear hereinafter.

lhe foregoing objects are accomplished by reacting a slight excess of a3,5 dialkoxy balkanol, 3,5,x-polyalkoxy-l-alkanol, or mixtures of suchalkanols with an organic dicarboxylic acid in the presence of one molper cent or less of an acidic catalyst, such as sulfuric andhydrochloric acid, preferably p-toluenesulfonic acid, at a temperaturerange of 120-l50 C. under conditions leading to the removal of water bydistillation.

The foregoing allranols are characterized by the following generalformula:

wherein R, represents an alkyl, such as methyl, ethyl, propyl,isopropyl, butyl, isobutyl, hexyl, and the like, aryl, e. g., phenyl,naphthyl, tolyl, and the like, aralkl, e. g., benzyl, phenethyl,

menaphthyl, and the like, or alkoxyalkyl, such as mcthoxymethyl,methoxyethyl, methoxypropyl, methoxybutyl, ethoxyethyl, ethoxypropyl,ethoxybutyl, propoxymethyl, propoxyethyl, propoxybutyl, butoxymethyl,butoxyethyl, butoxypropyl, and the like, and n represents a positiveinteger ranging from 2 to 10.

The dialkoxy-l-alkanols and polyalkoxy-l-allranols characterized by theforegoing formula are prepared according to the procedure described inthe application of Samuel A. Glickrnan, Serial No. 206,519, filedJanuary 17, 1951, now United States Patent 2,618,663, issued on November18, 1952, and entitled Production of Polyether Alcohols, bysimultaneously hydrolyzing and reducing polyet-her alkanol acetals tocorrespond" ing polyether alcohols in an aqueous solution containingcatalytic quantities of hydrolyzable salts of mineral and organic acidsin conjunction with Raney nickel catalyst and hydrogen at moderatetemperatures and pressures.

It is to be noted that the properties of the 3,5

diallioxy and 3,5,x-polyalhoxy-l-allranols pre pared according to theprocess disclosed in the aforementioned application, which hereinafterwill be referred to as 3,5,x-polyalkoxy-1-alkanols to indicate that analkoxy group is on alternate carbon atoms of the alcohol, will vary withthe nature of the alkoxy groups. These alkanols are colorless liquidscharacter zed by complete miscibility in organic solvents, such asaliphatic alcohols, ketones, esters, glycol ethers, aromatic solvents,and aliphatic petroleum ethers and naphthas. The complete miscibility inaliphatic hydrocarbons is in sharp distinction to the polyethyleneglycols which are virtually insoluble in these solvents. It can bereadily seen that the solvent applications of these diandpolyalkoxy-laliranols are numerous. These materials may serve aseffective replacements for the polyethyL- one glycols and lower glycolsin applications where low hygroscopicity, wide solvent power and lowerviscosity are of value.

In physical properties, the 3,5,x-polyalkoxy-lallranols rather closelyresemble the polyethylene glycol ethers and it has been found that thecorresponding polyethoxy 1 alkanols rather closely resemble thepropylene glycol ethers since they are somewhat less water soluble,i..e., not completely Water soluble, than the corresponding polymethoxy1 a kanols. As the molecular weight of the alkoxy group of the alkanolsincreases, the water solubility of the compounds decreases, and it hasbeen found that the 3,5,x-polybutoxyalkanols are quite water solublealthough the corresponding 3,5,x-methoxypolyalkanols are completelywater soluble.

As examples of dicarboxylic acids ranging from 6 to 12 carbon atomswhich can be esterified with the alkanols characterized by the aboveformula, the following are given:

Adipic, HOOC(CH2) 4-COOH Pimelic, HOOC(CH2) 5-COOI-I Suberic, HOOC(CH2)s-COOH Sebacic, HOOC-(CI-Iz) 8-COOH Hendecanedioic, HOOC(CH2)9-COOHDodecanedioic, I-IOOC-(CHz) ioCOOl-l Aromatic dibasic acids, such asphthalic, isophthalic, terephthalic, diphenic, pyrocholoridanic, or theanhydride and substitution products of phthalic acid, such as:

may also be employed.

When these acids are esterified with the foregoing alkanols, the estersobtained exhibit more favorable properties with respect to volatilityand water extractability than many of the presently available commercialplasticizers. The esters show an excellent range of compatibility withstock vinyl resins, such as polymers of vinyl chloride, copolymers ofvinyl chloride and vinyl acetate, cellulose ether and cellulose estercompositions. The compatability results in improved ease of milling thepolyvinyl and cellulosic sheets and the compounding of molding andcasting solutions. In particular, the esters confer low temperature flexproperties to the plasticized films. This feature is exceedinglyimportant since brittleness of films at low temperatures is a drawbackto the use of many resins and films therefrom. Vinyl resins andcellulose ether and ester films employing the esters prepared inaccordance with the present invention show excellent properties withregard to the absence of bloom, which is characterized by the exudationof the plasticizer from the film and results in brittleness and poorappearance of the films. Vinyl resins, cellulose esters, mixed celluloseesters, and cellulose ethers plasticized with the esters of the presentinvention show an exceedingly high degree of water resistance which issuperior to many of the presently employed plasticizers. Thecharacteristics imparted by the esters of the present invention to vinylresins, cellulose ether and ester compositions, as will be illustratedhereinafter, are believed to arise from the structure of the alcoholcontaining a straight chain carbon skeleton with appending ether sidechains. These ether linkages provide a high degree of association withthe vinyl resin, cellulose ether and ester composition,- thus conferringmany of the beneficial atof which time the distillation of water waspractitributes imparted by these esters. i cally complete. The cooledliquid was taken up As pointed out above, the esters are prepared inasuitable solvent, washed with dilutesoda soluby esterifying aslightexcess of thealkanol with a tion followed by distillation at reducedpressure. dicarboxylic acidoi from 6 to 12 carbon atoms 5 There wereobtained 90 parts of bis-3,5-dimethin the presence of an acidiccatalyst. The use of oxyhexyl sebacate boiling at 210-215 C. at 0.2

awaterazeotropingsolventgsuch as benzeneor mm. (mercury gauge), 'n1.4499, c14 0.9994. toluene, may be employed in the esterification Thecalculated analytical figures for CzsHscOs are since it affords asmoothreaction with lower opcarbon per cent 63.63, hydrogen per cent10.27,

crating temperatures, less color formation, more found r n per cent63.77, hydrogen per cent rapid removal ofxwater, and better yields than10 33 The yield is 73% of th th ti L those reactions inwhich suchasolvent is absent.

The use of decolorizing carbon either at the be- Emmllle II W ll 11 11--CH1CH- -CH2OH20C(CH2)4C-OCHI-CH2[H$CH2- H i $0113 2 l 00H, 1 inning ofthe esterificationtreaction orin the bis-3l5-dimethoxyhexyl fldipateworking up procedure yields faintly'colored solu- 2 The procedure ofExample I was followed with tions. The latter is an important. featuresince the exception that 51 parts of sebacic acid were it dispenses withthe distillation of the ester, par-- replaced by 37 partsi of adipicacid. Therewas ticularly the high molecular esters. The esters obtainedbis-3,5-dimethoxyhexyl adipate, boiling prepared in accordance with thepresent invenpoint 195-l98 C. at 0.2 mm. (mercury auge),

tion are characterized by the following general 12 1.4482, 014 1.0240-The calculated analytical formula: I figures for 0221-14208 arecarboniper cent 60.81,

. on I: tn wherein R and n have the same values as above, hydrogen percent 9.74, found carbon per cent and R represents a member selected fromthe and hydrogenrpel' cent class consisting of polymethylene chains offrom Example III 4 to 10 carbon atoms and the residues ofdicarbis-3,5-dibutoxyhexyllphthalate boxylic acids of the benzene andnaphthalene 3. i t yheX n01 w pr p by f win series. By residue is meantthat portion of the h general procedure f e a stated appl cadicarboxylicacid which carries the two carboxyl tion by subjecting 146 Parts of3,5'dibHtOXY-1" groups thereof, in other words, the residue to hexanatdibutyl 5 1 parts of water 1 part .whichthe two carboxyl groups areattached in t of p'toluenesulfomc and 15 parts Raney the free acid.

The following examples will serve to illustrate certain ways in whichthedicarboxylic acids are esterified with the 3,5 di a1koxy-, and3,5,x-polysquare inch at 90-95 C. The mixture was filtered from Raneynickel and distilled. .The 3,5-

dibutoxyhexanol boiled at 98-99 C. at 0.3 mm;

'alkoxy-l-alkanol, andmixture of such alkanols to l 97 parts ofdimethylphthalate 1 part of h l form the esters which are applied asplasticizers drous sodium methoxide and 2 5 parts f 3 5 for 0611111038ether and cellulose BS1381. composidibutoxyhexano] were placed in a,glass reactor tions. It is to be clearly understood that these with anattached fractionating column. The conexamples are not to be. construedin anyway as tents were heated at 120140 C. for 4 hours dur limiting theinvention. 1 ing which time there were collected 30 parts of H l g.methanol. The residue was subjected to vacuum Example] distillationyielding 280 parts of bis-3,5-dibutoxy- H[CHz-(|JH CHzCHa O (OHz) -Ocurr n m nent- H OCH: 2 QCHa 2 b w' t l hexyl phthalate, boiling pointof 210-215 C. at parts of 3.5-dimethoxy-l-hexanol (prepared .1 mm.according to Example I of the aforestated patent Example IV H 11-ont-on- CH2CH2 Z)l0 OCHz-CHz-[$H-CH2]H I: OCH: 3 l. OCHa :4application) were placed in a glass reactor with 51 3,5,Hrimeih0xy0cty1fiodecanedioate parts of sebacic acid and 0.1 part of p-toluenesul- 55parts of 3,5,7-trimethoxy octanol (prepared fonic acid. The mixture washeated in a nitrogen according to Example V of the said application),

atmosphere at -150 C. for 3 hours at the end 75 29 parts ofdodeoanedioic acid, parts oftolunickel to hydrolysis reduction at 1000lbs. per

ene, and 0.5 part of p-toluenesulfonic acid were replaced in a glassreactor equipped with a constant water separator. The mixture was heatedat 120-125 C. for 1 to 2 hours during which time the theoretical amountof Water was collected. The cooled mLxture was treated with dilute sodasolution and distilled at reduced pressure. There were obtained 60 partsof ,7-trime X5/ooty as, for example, cellulose acetate, cellulosetriacedodecanedioate, boiling point of at tate, celluloseacetate-propionate, cellulose acemm. (mercury gauge), n 1.4510. The yild is 10 tate-buty'rate, cellulose nitrate, cellulose nitrateofthetheor-etical. acetate, ethyl cellulose, benzyl celulose, and the.tures'of such alkanols with o-ethylglycolic acids and mixtures ofadipic, pimelic, suberic, azelaic, sebacic, hendecanedioic, anddodecanedioic acids were prepared as in the foregoing examples. Theesters prepared as above are compatible with all of the previouslymentioned vinyl resins,cellulose ethers and esters commerciallyusedysuch Example V like. The esters may be incorporated into moldo o H-CH2-CH oH20H2o-PJ(oH2)4, :o GHQ-CH2- CHCH -H l: CI)CH 4 i: CHa 4bis-3,5, ,9-tetra et o y adipate ing powders of vinyl resins, celluloseethers and 104 parts of 3,5,'7,9-tetramethoxy-1-decanol obsters r intosoluti n whi h r n rma ly.pr tained as a fraction from mixture ofalcohols prep ed for films, lacquers, dopes, a laminating paredaccording to Example III of said aforemen solutions. The concentrationor amount to be tioned application, 22 parts of adipic acid, 100 used asa plasticizer will depend, of course, on the parts of toluene, and 0.1art of p-toluenesulfonic y of vinyl r sin, cellulose ether or estercomacid were placed in a glass reactor equipped with 25 position p y Tap m amounts a constant water separator. The mixture was to be employedfor any particular composition heated at the reflux point for 4 hoursduring can be very readily determined by simple routine which'time thetheoretical amount of water was pot e p e In general. w ver, tcollected. The cooled mixture was treated with amount for moldingpowders may range from dilute soda solution and washed several times 20to 40% of the powder, in solutions for films with water. The water-oilmixture was allowed anywhere from 3 to 6%, in lacquers about 2 to toseparate and the heavy oil collected. There 5%, in dopes from 40 to 50%,and in laminating were obtained 91 parts ofbis-3,5,7,9-tetramethsolutions from 3 to 6%. All of these percentagesoxydecyl adipate in a yield of 90% of the theoare based on the weight ofthe vinyl resin, celluretical. lose ether or ester composition.

Example VI The following example illustrates the applicao o H -OHCHCH2CHzO%,(C 2)a i0CHzCH2- -CH-CHz- H OCHa 5 l: 30:53 3

bis-3,5,7,9,1 1-pe ame o Subemte tion of the foregoingesters asplasticizers and 190 parts of 3,5,7,9,ll-pentamethoxy-Ldo- 40 theimprovedresults obtained thereby when comdecanol (prepared according toExample IV of pared with currently used plasticizers. the saidapplication), 44 parts of suberic acid, 150 parts of toluene, and 0.1part of p-toluene Example IX sulfonic acid were placed in a glassreactor A film of Cellulose acetate 0f 5 mil thi ess, equipped with aconstant water separator. The 45 lmina 58.4 to 59% Combined acetic acid,was mixture was heated at the reflux point for 3 prepared y Ca theComposition given e ow hours during which time the theoretical amount011 a Clean, glass p ate With a doctor blade, folof water was collected.The cooled mixture was 7 lowed by air drying or 48 hours at roomtemtreated with dilute soda solution and the solvent pel'atllre at tro eto p t blushing distilled at reduced pressure. There were ob 50 0f otherPhysicaldamage to the film. The film tained 175 parts ofbis-3,5,7,9,11-pentamethoxy- Was then removed from the glass plate andfurdodecylsuberate of a yield of 80% of the theoretither dried for 2hours at 60 C. in the presence CELL of freely circulating air.

Parts Example VII.-3,5,ar-alcohol esters of adipic acid Celluloseacetate (containing 58% acetic acid) 00 parts of a .mixture of alcoh lsns sti Dimethylphthalate :T g of 30% of 3,5-dimethoXy- 0f Methylenechloride 50 3,5,7-trimethoXy-l-octano1, 10% 0f 3,5,7,9"tet1"a- Ethylenechloride 22 methoxy-l-decanol, and 5% of pol 60 Absolute ethanol 1ocohols of the type of 3,5,7,9,xpolymethoxy alkanol, and 219 parts ofadipic acid were treated as in Example v to yield a mixture of esterswere prepared in WhlCh the plasticizers were diwhich Were compatiblewith the usual cellulose methXYethY1Phtha1ate. butyl cellosolve l tethers and esters with very low volatility and low bls'3'methoxybutyladlpate, and Plastlcizers as t tractabilit p p red above. wa er ex ySamples of all of the films were placed in air circulating oven for 24hours at 100 C. In another instance, samples were immersed in waterExample VII was repeated with the exception at room temperature for 48hours, removed, that 219 parts of adipic acid were replaced by rinsedwith distilled water, and dried for 2 hours 225 parts of phthalicanhydride. The mixture at 60 C. The superiority of films containing theof esters obtained showed excellent compatability plasticizers of thisinvention over similar films with the usual cellulose ether and esters.containing prior art plasticizers in resistance to In a similar manner,esters of 3,5-dialkoxy-lloss of wei t under this treatment iSBhOWn inalkanols, 3,5,x-polyether-l-alkanols, and mix- Table 1.

In like manner, films of the same thickness Example VIII TABLE 3.

Water Extrao- Volatility, tion, Percent o om cos 0 er Hammers 0. After24 48 Hours in Hours at Water at Room Temperature Dimethylphthalate. 2827. 9 2. 7 D methoxyethylphthalate 209-261/20 mm.-- 7. 1 2. 1Bis'3-methoxybutyl adipate. 129/0.16 mm 10. 1 6. 9 Bis-Elethoxybutyladipate-.. 154/0.1 mm 9. 3 1. 0 165/02 mm 7. 8 1. 5 ISO/0.2 mm 6. 1 1. 7Bis-3 butoxybutyl hthalate ISO/0.2 mm 5. 0 0. 5 Bis-3,6-dimethoxyexylsebacate- 214/02 mm 2. 8 1. 2 B1st-3,5-dimethoxy-hexyl phthal-207210/0.3 mm 3. 1 1. 5

a e. Bis-3,5-diethoxy-hexyl adipate. 207208/0.45 mm--- 5. 1 2. 2Bled-ii,5%,9-tetra-methoxydeoyl Not distillable.. 4. 8 2. 0

a a 3:1 Afizohol esters of adipic acid Mixtures 3.:

3:1 Alcohol esters of phthalic do anhydride 1 3:1 alcohols composed ofthe following approximate proportions:

30% 3,5-dimethoxy-1-hexanol 20% 3,5,7-trimethoxy-1-octanol 10%3,5,7,9-tetramethoxy-1-decanol 5% higher polymethoxy alcohols of thetype 3,I5,7,9,x-polymethoxy-1-alkanol, as

characterized by the general formula wherein n represents 2 to 3.

We claim: sisting of phenylene, diphenyleneand naphthyl- 1. Adicarboxylic acid ester of alkoxy-l-alkanol ene radicals, and nrepresents an integer of from characterized by the following formula: 2to 16.

OR i. and mixtures thereof, wherein R, represents a 2.Bis-3,5-dimethoxyhexyl sebacate having the member selected from theclass consisting of following formula:

alkyl of not more than 6 carbon atoms, lower 3. Bis-3,5-dimethoxyhexyladipate having the alkoxyalkyl in which the alkyl groups containfollowing formula:

not more than 4 carbon atoms, phenyl, naphthyl, 4. Bis-3,5-dibutoxyhexylphthalate having the tolyl, and benzyl, phenethyl and menaphthylfollowing formula:

groups, R represents a member selected from the 5. Bis 3,5,7trimethoxyoctyl dodecanedioate class consisting of pols/methylene chainsof from having the following formula:

4 to 10 carbon atoms and the cyclic hydrocarbon 6.Bis-3,5,7,9-tetramethoxydecyl adipate havradicals of dicarboxylic acidsof the group coning the following formula:

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,706,639 Van Schaak et a1. Mar. 26, 1929 2,075,107 FrazierMar. 30, 1937 2,302,743 Carruthers Nov. 24, 1942 2,349,414 Ferrer May23, 1944 2,497,433 Blake Feb. 14, 1950

1. A DICARBOXYLIC ACID ESTER OF ALKOXY-1-ALKANOL CHARACTERIZED BY THEFOLLOWING FORMULA: